A food journal is a GREAT idea. I do it and it really makes you think about what you are putting into your body. It also acts as a record of what worked and what did not, and that is beneficial to this journey.
In my food journal I have breakfast, lunch, dinner and two snack ares, a spot to write down what anti-fungals I used that day, and an area for notes.
It’s an invaluable record and reference.